1. Field of the Invention
The present invention relates to a card reader. More specifically, the present invention relates to a configuration for preventing fraudulent use of a card medium in a card reader.
2. Description of Related Art
In card reader 101 of conventional technology, as shown in FIG. 10, the security of card reader 101 is achieved by providing shutter 102 that is opened or closed by a solenoid, for example, in a card insertion port to prevent the insertion of a foreign object other than card medium 103, and also to prevent theft by fraudulent removal of card medium 103 which is caught in card reader 101.
Card reader 101 is provided with shutter 102 such that if card medium 103 is inserted from insertion port 104, shutter 102 retreats from the card path and the inserted card medium 103 is taken into card reader 101.
Moreover, if card medium 103 enters beyond shutter 102, the shutter 102 closes to prevent withdrawal of card medium 103 by wrongful actions.
Here, an ill-intentioned person may tamper with card reader 101 so that when a rightful user inserts card medium 103 into card reader 101, it is caught inside. As soon as the owner of card 103 leaves the site, card medium 103 is removed to be used for fraudulent actions.
To prevent such fraudulent actions, a card reader has been developed in which the card medium is deformed by blowing hot air when abnormal stopping of card medium is detected in the unit to make the removed card medium unusable. A card reader has also been developed in which a sharp needle is pressed on the magnetic stripe of the card medium to destroy data recorded in the magnetic stripe, when abnormal stopping of the card medium is detected inside the unit.
However, a card reader of the aforementioned type which deforms the card medium by means of blowing hot air or the like is not preferable because the card medium is damaged even though the card medium stopped abnormally for reasons other than abnormal stopping for wrongful removal.
Moreover, in a card reader of the type in which a sharp needle is pressed onto a magnetic strip, the effects of data destruction cannot be expected for the card medium having an IC chip, because the IC chip cannot be destroyed.
Hence, room for further improvement remains for the conventional card readers.
In other words, the improvement should be able to deal with attempts by a wrongdoer to remove the card medium by exerting force to pull out the card medium that is stronger than the locking force that keeps the card medium in the holding position, whether by piercing the card medium with a sharp-pointed member or by pressing a rubber pad on the surface of the card medium.
Furthermore, in a structure in which wrongful removal is prevented by hooking a lock pawl to the surface of a card medium, a locking force derived from the lock pawl is effective when a wrongdoer applies a force in the direction in which the card medium is pulled out.
However, if the wrongdoer applies a force in the direction in which the card medium is pushed in, and alternates the pulling and pushing forces persistently in an attempt to wrongfully remove the card medium, the lock pawl cannot apply a locking force in the reverse against the push-in force.
Accordingly, the present invention-has the purpose of providing a card reader from which an IC card cannot be pulled out in a usable state when the IC card has been inserted.
The present invention also has the purpose of providing a card reader that effectively prevents a card medium inserted from the card insertion port from being removed by a wrongdoer and used fraudulently.